I was excited to receive my Canon 5D MkIII a few weeks back. The first thing I did was set it up on my off-set shoulder rig. This rig worked well for me with the MkII as it was the perfect combination of stability and weight. The first thing I noticed was that the digi finder I was using on my 5D was no longer usable on the enlarged lcd screen of the mkIII. This is a good thing and the resolution is really nice. Having just forked out 5K for the mkIII I didn't want to spend much more money so I went about making a sunshade instead.
I wanted to make the sunshade strong enough to make full contact with my face giving me that fourth point of contact with the rig. I forgot to mention in the video that I added a couple of strips of sponge seal to the back edges of the sunshade for added comfort.
Overall I am pretty pleased with the result. hope this is of use to all you DIYers out there.